In order to determine the pressure in the extracorporeal blood circulation, the latter may be provided with “tap lines” (pressure derivations) in order to pass the pressure in the extracorporeal circulation on to a pressure sensor by means of a gas column. These tap lines represent “open” locations of the extracorporeal circulation and must be protected for reasons of hygiene, i. a. by sterile filters (“transducer protector”). A failure of these filters or protective means in general can expose the patient to the risk of a cross-contamination.
Another known method for measuring the extracorporeal pressure is implemented with the aid of so-called “pressure domes”. Here the tubing system remains closed, with the pressure values being transmitted from the blood to the machine via an impermeable membrane. To this end, a reusable pressure sensor is disposed in the extracorporeal circulation. The sensor has to satisfy considerable demands to hygiene, drift of measurement values, etc., over a comparatively long period of time such as two years to ten years.
Accordingly, pressure sensors for one-way articles or disposables which transmit measured values by wire or also wirelessly are also known in the prior art. In the example of the extracorporeal blood circulation, they are situated inside the one-way tubing system and are discarded together with the disposable following the treatment. Such pressure sensors for disposable devices do, however, require a calibration that must be performed individually for each sensor, whereby their manufacture is rendered costly. The supplier of the sensors moreover has to supply calibration data in separate data memories together with the sensors, as is described, e.g., in U.S. Pat. No. 6,695,806 B2 to CHF Solutions. It is in particular the high costs caused by the connections necessary for calibration of each individual sensor which is prohibitive for a use of these sensors in the large and very large piece numbers in which most one-way articles are manufactured and used.